Indicator switch assembly

ABSTRACT

An indicator switch assembly for filters wherein a piston responsive to differential pressures within the filter housing is movable to indicate the differential between said pressures and to move a finger member between a pair of closed switch arms to separate the same and break the circuit therebetween, continued movement of said finger member being effective to close at least one of said switch arms with a third switch arm to create a circuit therebetween.

United States Patent Kudlaty [54] INDICATOR SWITCH ASSEMBLY [72] Inventor: Walter J. Kudlnty, Elmhurst, Ill.

[73] Assignee: Marvel Engineering Company, Chicago,

[22] Filed: July 7, 1970 [21] App1.No.: $6,151

Related U.S. Application Data [63] Continuation of Ser. No. 771,924, Oct. 30, 1968. aban- 1 .t V... 7W

[52] US. Cl. ..200/167 R, 116/70 [51] Int. Cl. ..H01h 9/16 [58] Field otSearch ..200/82, 153 M, 167 R, 172 R,

[ 1 Apr. 4, 1972 [56] References Cited UNITED STATES PATENTS 2,764,645 9/1956 Smith ..200/82 1,781,962 11/1930 Stirling ..200/167 R 3,054,880 9/1962 Harman, Jr. ..200/ 167 R Primary Examiner-H. 0. Jones Attorney-Parker, Carter and Markey [5 7] ABSTRACT An indicator switch assembly for filters wherein a piston responsive to differential pressures within the filter housing is movable to indicate the differential between said pressures and to move a finger member between a pair of closed switch arms to separate the same and break the circuit therebetween, continued movement of said finger member being effective to close at least one of said switch anns with a third switch arm to create a circuit therebetween.

2 Claims, 2 Drawing Figures INDICATOR SWITCH ASSEMBLY This application is a continuation of Ser. No. 77 l ,924, filed Oct. 30, 1968, and now abandoned.

SUMMARY OF THE INVENTION A piston is movable within a housing in response to fluid pressure differentials within a filter housing with which the indicator housing communicates. A finger member is movable with the piston and externally of the indicator housing, the finger member having inclined surfaces movable between a pair of contacting switch arms to separate the same and break the circuit therebetween. The inclined surfaces of the finger member diverge, whereby continued movement of the finger member moves said switch arms further apart to bring at least one of said switch arms into contact with at least one third switch arm and to create a circuit therebetween. The switch arms and finger member surfaces are designed to provide well delineated and defined indications of the filter housing pressure variances and thus to indicate the condition of a filter member therewithin.

This invention relates to filters, and particularly to filter indicators.

One purpose of the invention is to provide a filter indicator effective to operate an electrical switch member in response to pressure differentials within the filter housing.

Another purpose is to provide a filter indicator and switch assembly having means for breaking a first circuit and making a second circuit.

Another purpose is to provide a filter indicator and switch assembly effective to break a first electrical circuit in response to a first pressure differential within a filter housing and to make a second electrical circuit in response to a second pressure differential within a filter housing.

Another purpose is to provide a filter indicator switch assembly effective to break a first circuit in response to a first pressure differential within a filter housing to provide for no electrical circuits through said indicator switch assembly in response to a second pressure differential within said housing and to make an electrical circuit through said indicator switch assembly in response to a third pressure differential within said filter housing.

Another purpose is to provide an indicator switch assembly responsive to pressure differentials within a filter housing and of maximum simplicity in manufacture and use and of maximum reliability.

Another purpose is to provide an assembly capable of simultaneous visual indication and electrical circuit control.

Other purposes will appear from time to time during the course of the specification and claims.

BRIEF DESCRIPTION OF THE DRAWINGS The invention is illustrated more or less diagrammatically in the accompanying drawings wherein:

FIG. 1 is a side elevation with parts in cross section; and

FIG. 2 is a top plan view of the switch portion of the assembly of the invention. Like parts are indicated by like numerals throughout the specification and drawings.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring now to the drawings, the numeral 1 generally designates an indicator housing. The indicator housing 1 may be formed of transparent material such as plastic, for example. The housing 1 has an aperture 2 communicating through passage 3 with an internal chamber 4. It will be observed that the chamber 4 is enlarged in the area of its communication with passage 3, i.e. at the bottom of housing 1 as the parts are shown in the drawings. The chamber 4 includes an elongated, vertical portion 4a in which a piston member 5 is reciprocal.

A second aperture or opening is formed in the housing 1 and preferably in alignment with the opening 2. The aperture 10 communicates through passage 11 and angularly positioned passage 12 with the upper or opposite end of chamber 4a from that at which the enlargement 4 is positioned. Within the chamber portion 4a, the springs 15,16 engage the upper end of chamber 4a and the inner conformations within piston 5 to urge the piston 5 toward passage 3.

The structure thus far described may be more fully understood by reference to applicant's copending application, Ser. No. 658,20l, filed Aug. 3, I967, now US Pat. No. 3,41 1,477 and entitled Pressure pressure Differential Indicator. As may be there observed, the housing 1 may have positioned therein suitable indicia elements (not shown herein) along which the upper edge 5a of piston 5 is movable to provide visual indication of the position of piston 5 and the pressure difierential within the filter housing (not shown).

It will be understood that a filter housing, which may take a variety of forms, includes an inlet and an outlet and a filter element between said inlet and outlet. As is well known, the inlet of the filter housing would communicate with opening 2 in indicator housing 1 and the outlet of the filter housing would communicate with opening 10 in housing 1. Thus an increase in contamination of the filter element between the inlet and the outlet, and thus between the openings 2 and 10, would produce a higher pressure at opening 2 than that at opening 10. With the pressures on opposite sides of piston 5 thus varying, the higher pressure below piston 5 within chamber 4, causes piston 5 to rise against the action of springs 15 and 16, as is more fully described in the aforementioned application.

Secured to the piston 5, as at 20, is a rod 21 extending from the piston 5 and into an upwardly or outwardly open, threaded well 22 formed in indicator housing 1. The seal 23 is seated in well 22, as is the bushing 24, through both of which rod 21 extends.

A threaded fitting 25 is threadably received within well 22 and includes an axial bore 26 extending through the fitting 25 and receiving a finger member 27 carried by rod 21 for reciprocation into and outwardly of the bore 26. Finger member 27 includes a frusto-conical end surface 28 having the outwardly, downwardly diverging circumferential surface 29.

The fitting 25 serves the additional function of mounting and supporting a switch arm bracket 30. Secured to the switch arm bracket 30 are switch arms 31,32,33. It will be observed that switch arms 31,32 are substantially parallel and include end portions 31a, =a positioned to overlie, as the parts are shown, the bore 26, the portions 31a, 3211 being normally spaced apart a distance less than the maximum diameter of finger member 27. End portions 31a, 32a include curved, converging end segments 31b, 32b which constitute contact portions for the arms 31,32. Since the arms 31,32 may have rearward segments clamped as by the blocks and fasteners indicated generally at 40,41, it will be understood that the contact segments 31b, 32b are yieldingly urged toward each other and into circuit-making contact therebetween.

The contact arm 33 is similarly clamped by elements 40,41 and includes a bent contact segment 33a spaced from one of the arms 31,32, the arm 32 being selected for illustration in FIG. 2.

It will be understood that the arms 31,32,33 are suitably connected in known manner with external elements such as machinery, remote indicators, control panels or the like. None of said remote items are shown, since their nature does not affect the invention disclosed and claimed herein. It will be understood, however, that the arms 31,32,33 may be suitably connected electrically with a wide variety of items without departing from the nature and scope of the invention.

The use and operation of the invention are as follows:

When contamination builds on the filter element within the filter housing (not shown) piston 5 will rise, as the parts are shown, providing a visual indication of the fact that contamination has caused variance in pressures within the filter housing. At the same time, the inclined surface 29 of member 27 will be moved between the arm segments 31a, 32a.

When the piston 5 and member 27 have moved a predetermined distance in accordance with a preset variance of fluid pressure within the filter housing which is in turn corresponding with the amount of contamination of the filter element therein. Since the finger element 27 is spaced from the arms 31,32, as may be clearly seen in Figure l, and since the initial penetration of the member 27 between the arms 31,32 will not cause a separation of said arms, it will be realized that a visual indication of the fact that the piston has moved along the indicia (not shown) is provided prior to separation of the arms 31,32. As the surface 29 of member 27 further penetrates between the arms 31,32, a gradual separation thereof will occur. Upon separation of the arm segments 31b, 32b, the electrical circuit between the arms 31,32 will, of course, be broken.

As shown in the drawings, the end segment 33a of arm 33 is spaced from the arm 32. Hence a null period in which a circuit is nonexistent through any of the arms 31,32,33 will occur. Continued penetration of the member 27 between the arms 31,32 will, however, cause the arm 32 to move sufficiently toward the end segment 33a of arm 33 to contact the same and thus to provide or to make a circuit between or running through the arms 32,33.

It will be understood that the position of piston 5, the amount of pressure variance within the filter housing and the amount of filter element contamination productive of said variance will all be correlated so that the indication provided by the alignment of piston end a with the appropriate indicia will accurately reflect the condition within the filter housing. For example, the indicia may consist of green and red color bands, with the green band being below the red, as the parts are shown. In such event, the edge 5a of piston 5 will move along the green toward the red as contamination builds and pressure variance increases within the filter housing. At an appropriate point in such travel along said indicia, the circuit will be broken across the arms 31,32. At this point the edge 5a, for example, may have just reached the boundary between the green and red indicia portions. As the contamination and pressure increases and the edge 5a moves deeper into the red indicia portion the electrical circuit will be created across arms 32,33.

Thus, for example, an electrical circuit energizing or activating certain machine elements may be broken upon the reaching of an initial contamination level. Additional contamination may then produce an electrical circuit effective to provide shutdown of the entire machinery, more positive indication of trouble, or the like.

It will be realized further that fluids subjected to temperature influences may prove of greater viscosity under cold or start-up" temperatures. Such increased velocity would tend to provide a false indication of contamination, since the pressure required to force such fluid through the filter element within the housing would be greater than that normally required when the fluid is warmer and thus of less viscosity. With the present system, however, an initial movement of piston 5 does not cause an effect upon the switch arms 31,32 or 33. Nonetheless, the presence of contamination on the filter element at a level which would correspond to the situation obtaining during start-up would produce a permanent positioning of the piston 5 alongside the indicia and would thus produce an indication to the operator that the position of piston 5 is due to contamination and not to the greater viscosity of fluid under cold or start-up" conditions.

lclaim:

1. For use with a filter housing having an inlet, an outlet and a filter element between said inlet and outlet, an indicator housing having a transparent wall portion, a chamber in said indicator housing, a piston reciprocal in said chamber, a first passage communicating said chamber on one side of said piston with said filter housing inlet, a second passage communicating said chamber on the other side of said piston with said filter housing outlet, said chamber being closed except for said first and second passages, a rod secured to one side of said piston and extending outwardly of said indicator housing, a finger member secured to said rod externally of said indicator housing, first and second switch arms carried by said indicator housing and aligned with said finger member, said switch arms being yieldingly urged in contact with each other, said finger member being movable between and into contact with at least one of said switch arms in response to movement of said piston in one direction, said piston being movable in said direction in response to a pressure differential between said first and second passages, said piston being dimensioned to move a predetermined distance before contact of said finger member with either of said switch arms, said finger member having an end surface effective to urge at least one of said switch arms away from and out of contact with the other of said switch arms in response to continued movement of said finger member in said one direction, said piston having at least an edge visible through said transparent wall portion of said indicator housing and a third switch arm spaced from one of said first-named switch arms and of said first-named switch arms when said finger member has moved a further predetermined distance in said one direction.

2. The structure of claim 1 further characterized in that said finger member surface comprises a conical, inclined end surface, said end surface contacting said first and second switch arms simultaneously to separate and move the same in opposite directions in response to movement of said finger member in said one direction between said first and second switch arms and to urge said one of said first-named switch arms into contact with said third switch arm in response to further movement of said finger member in said one direction.

positioned for contact by said one 

1. For use with a filter housing having an inlet, an outlet and a filter element between said inlet and outlet, an indicator housing having a transparent wall portion, a chamber in said indicator housing, a piston reciprocal in said chamber, a first passage communicating said chamber on one side of said piston with said filter housing inlet, a second passage communicating said chamber on the other side of said piston with said filter housing outlet, said chamber being closed except for said first and second passages, a rod secured to one side of said piston and extending outwardly of said indicator housing, a finger member secured to said rod externally of said indicator housing, first and second switch arms carried by said indicator housing and aligned with said finger member, said switch arms being yieldingly urged in contact with each other, said finger member being movable between and into contact with at least one of said switch arms in response to movement of said piston in one direction, said piston being movable in said direction in response to a pressure differential between said first and second passages, said piston being dimensioned to move a predetermined distance before contact of said finger member with either of said switch arms, said finger member having an end surface effective to urge at least one of said switch arms away from and out of contact with the other of said switch arms in response to continued movement of said finger member in said one direction, said piston having at least an edge visible through said transparent wall portion of said indicator housing and a third switch arm spaced from one of said first-named switch arms and positioned for contact by said one of said first-named switch arms when said finger member has moved a further predetermined distance in said one direction.
 2. The structure of claim 1 further characterized in that said finger member surface comprises a conical, inclined end surface, said end surface contacting said first and second switch arms simultaneously to separate and move the same in opposite directions in response to movement of said finger member in said one direction between said first and second switch arms and to urge said one of said first-named switch arms into contact with said third switch arm in response to further movement of said finger member in said one direction. 